Machine for assembling members and providing a controlled amount of tolerance between the members



1957 A. .1. COLAUTTI ETAL 3, ,03

MACHINE FOR ASSEMBLING MEMBERS AND PROVIDING A CONTROLLED AMOUNT OF TOLERANCE BETWEEN THE MEMBERS Filed Oct. 11, 1965 7'5 #1 l I V INVENTORS W1 & 1 IR min-m..- '1 j/jff/cffihalgjg Quimm gone/d 5f Saszh:

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United States Patent 3,357,084 MACHINE FGR ASSEMBLING MEMBERS AND PRGVIDING A CSNTRULLED AMOUNT (IF TOLERANCE BETWEEN THE MEMBERS Albert J. Colautti, Windsor, Ontario, Canada, and Donald H. Suszko, Warren, Mich, assignors to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Oct. 11, 1965, Ser. No. 494,606 3 Claims. (Cl. 29200) This invention relates to a new apparatus for riveting.

Conventional riveting machines include apparatus for inserting a headed rivet through apertures in the members being fastened and then upsetting the rivet while the head portion is held against an anvil surface. This conventional riveting apparatus produces a tight riveted connection and is very undesirable in situations where a slight amount of tolerance or play is desired in the riveted assembly.

It is, therefore, an object of the subject invention to provide a riveting machine whereby a controlled amount of tolerance can be provided between the members joined in a riveted assembly.

In general, the invention features the use of an anvil having a cavity sized to support the outer perimeter of a rivet head and yet allow the center portion of the rivet head to be forced into the cavity upon actuation by a punch or other force-producing element. This distorting or dishing of the rivet head occurs prior to the upsetting of the rivet shank at the other end and results in a controlled amount of spring back upon completion of the upsetting operation. It is this controlled spring back which results in the amount of tolerance desired in the riveted assembly.

Other objects, features and advantages of the subject invention will become obvious upon reference to the following detailed description and the drawings depicting the preferred embodiment of the invention, wherein:

FIGURE 1 is an elevation view with parts in section showing a riveted assembly accomplished by use of the apparatus and method of the invention;

FIGURE 2 is an elevation view with parts in section of the apparatus of the invention as it is about to contact a rivet to result in a riveted assembly;

FIGURE 3 is the same view as FIGURE 1 at the instant where the apparatus of the invention has dished the head of the rivet;

FIGURE 4 is the same view as FIGURE 3 at the point where the apparatus has upset the shank portion of the rivet; and

FIGURE 5 is a view of a conventional riveted assembly.

More particularly, the apparatus of the subject invention includes a punch and an anvil 12. The punch 10 may be of any suitable material having properties sufiicient to withstand the forces developed in this type of operation and may be actuated by any suitable manual or power-driven mechanism (not shown). The punch 10 is seen to include a shank portion 14, a body portion 16, which is adapted to be connected to the actuation means, and a work-contacting end 18. The work-contacting end 18 includes force concentrating cross ribs 20 and 21 which extend axially therefrom.

The anvil 12 may also be of any suitable material having properties capable of withstanding the forces developed in such an operation. The anvil 12 may also be of any suitable size and shape and is supported on a base 22. The work-contacting end of the anvil 12 is seen to have a recess 24 which has an annular stepped shoulder portion 26.

A rivet 28 is shown passing through apertures in the members 30 and 32 which are to be assembled. The members 30 and 32 may be any two devices which are required to be assembled together. In this particular embodiment the member 30 is a lockbar plate and the member 32 an upper channel in a seat adjusting mechanism for an automobile. This particular embodiment was chosen because it is a situation where it is desired to have a controlled amount of tolerance between the lockbar plate and the upper channel to create a pivot permitting rotational movement of one relative to the other in a plane normal to the axis of the rivet, but not so as to allow rocking movement of one member relative to the other.

The rivet 28 is seen to include a relatively broad, flat head 34, an intermediate shank 36 extending through an aperture 38 in the member 30, and a lesser diameter shank 40 extending through an aperture 42 in the member 32.

The remaining discussion will be directed toward the operation of the subject invention as seen insequence from FIGURES 2 to 3 to 4 to 1.

As seen in FIGURE 2, the rivet 23 has been inserted through the members 30 and 32 and is resting on the stepped shoulder portion 26 in the recess 24 of the anvil 12. It can also be seen that the punch 10 has been moved to a position where it is about to contact the end of the shank 46 of the rivet 28. Moving to FIGURE 3, it is seen that the cross ribs 20 and 21 of the punch 10 contact the end of shank 40 of the rivet 28 first, thereby concentrating the displacement force in the center of the rivet 28 and forcing the center portion of the head 34 into the cavity 24 until it bottoms on the lower surface 44. At this point it is seen that the intermediate shank 36 of the rivet 28 has been displaced downwardly such that the member 32 is resting on the member 30. Moving to FIGURE 4, it is seen that once the head portion 34 of the rivet 28 has bottomed on the surface 44 in the cavity 24, the force of the punch It) then upsets the shank portion 40 in a radial direction. At the point shown in FIGURE 4 the members 30 and 32 are held tightly together under the force of the punch 10 and the holding action of the anvil 12. Moving to FIGURE 1, it is seen that when the punch 10 and anvil 12 are removed from the assembly, the rivet head 34 springs back a predetermined and controlled amount to thereby move the intermediate shank 36 and create a controlled amount of tolerance in the assembly between the members 34 and 32. The amount of this spring back is a function of the depth of the cavity 24, the properties of the material of the rivet 28, and the dimensions of the rivet head 34. Therefore, the depth of the cavity 24 should be designed for the maximum amount of tolerance expected between the upper surface of the intermediate shoulder 36 and the upper surface of the member 30. Hence, the procedure just described results in a riveted assembly whereby two members are assembled together with a controlled amount of tolerance built into the riveted assembly. It should be noted that the rivet head 34 does not have to bottom in the cavity 24 as it will still spring back an amount proportional to its displacement. Additionally, it should be clear that the displacements shown on the drawings are exaggerated for purposes of illustration. Furthermore, it is not essential that a shouldered rivet be used as a simple rivet with a shank of constant diameter would be likewise operable under the method of this invention.

FIGURE 5 shows a conventional riveted assembly, whereby a rivet 46 of the same type as that used in the present invention holds members 48 and 50 together. It can be seen that this conventional riveting method results in a tight riveted assembly. The only way a tolerance between the members 48 and 50 can be assured in the conventional riveting assembly is to use a rivet with the intermediate portion 52 being slightly longer than the thickness of the member 48. If this difference in size could be controlled with exact precision, the desired tol erances between the members 48 and 50 could be accomplished with a conventional riveting operation. However, in modern-day production assembly operations, it is extremely expensive and virtually impossible to com trol tolerances of assembly parts to the accuracy required to assure the desired tolerance between the members 48 and 50.

Hence, the conventional riveting method as shown in FIGURE 5 is extremely impractical for modern-day riveting assemblies wherein a controlled amount of tolerance between the members being assembled is desired.

The present invention provides a riveting machine whereby a controlled amount of tolerance between the members being assembled can be riveted into the assembly regardless of slight variations in the size of the rivet and the members being secured.

It should be clear to those skilled in the art to which it pertains that the present invention has many uses other than the embodiment shown and described and that many changes and modifications maybe made thereto without departing from the scope of the invention.

We claim:

1. A riveting machine adapted for assembling members together with a headed rivet which extends through apertures in said members, said machine comprising:

a punch upsetting said rivet on one side of said members being assembled together;

and an anvil including means for supporting the head of said rivet around its perimeter and having a cavity formed therein to receive the center portion of said rivet head upon its being displaced by said punch, said cavity allowing said head to be dished under the action of said punch and then to be sprung back a controlled amount after the rivet has been released from the action of saidpunch and said anvil.

2. A riveting machine as set forth in claim 1 wherein said punch has a protrusion at the center of its rivet contacting end which displaces the center of the rivet head prior to the main portion of said rivet contacting end upsetting said rivet.

3. A riveting machine adapted for assembling members together with a headed rivet which passes through apertures in said members such that a controlled tolerance results in the riveted assembly, said machine comprising:

a punch upsetting said rivet on one side of said members being assembled together;

and an anvil including means for supporting the head of said rivet around its perimeter and having a cavity formed therein to receive the center portion of said rivet head upon its being displaced by said punch, said cavity allowing said head to be dished under the action of said punch and then to be sprung back a controlled amount after the rivet has been released from the action of said punch and said anvil to thereby produce the desired tolerance in said assembly.

References Cited UNITED STATES PATENTS 1,085,878 2/ 1914 Shipley 29200 2,060,394 11/ 1936 Hier-ing 29-444 2,365 ,l47 12/1944 Speller 29208 2,672,699 3/ 1954 Morgan 29437 2,987,811 6/1961 Acres 29437 3,138,977 6/ 1964 Aitken 29--200 THOMAS H. BAG-ER, Primary Examiner. 

1. A RIVETING MACHINE ADAPTED FOR ESTABLISHING MEMBERS TOGETHER WITH A HEADED RIVET WHICH EXTENDS THROUGH APERTURES IN SAID MEMBERS, SAID MACHINE COMPRISING: A PUNCH UPSETTING SAID RIVET ON ONE SIDE OF SAID MEMBERS BEING ASSEMBLED TOGETHER; AND AN ANVIL INCLUDING MEANS FOR SUPPORTING THE HEAD OF SAID RIVET AROUND ITS PERIMETER AND HAVING A CAVITY FORMED THEREIN TO RECEIVE THE CENTER PORTION OF SAID RIVET HEAD UPON ITS BEING DISPLACED BY SAID PUNCH, SAID CAVITY ALLOWING SAID HEAD TO BE DISHED UNDER THE ACTION OF SAID PUNCH AND THEN TO BE SPRUNG BACK A CONTROLLED AMOUNT AFTER THE RIVET HAS BEEN RELEASED FROM THE ACTION OF SAID PUNCH AND SAID ANVIL. 